Transforming Growth Factor β1 Regulates Melanocyte Proliferation and Differentiation in Mouse Neural Crest Cells Via Stem Cell Factor/KIT Signaling

Abstract

Stem cell factor is essential to the migration and differentiation of melanocytes during embryogenesis based on the observation that mutations in either the stem cell factor gene, or its ligand, KIT, result in defects in coat pigmentation in mice. Stem cell factor is also required for the survival of melanocyte precursors while they are migrating towards the skin. Transforming growth factor beta1 has been implicated in the regulation of both cellular proliferation and differentiation. NCC-melb4, an immortal cloned cell line, was cloned from a mouse neural crest cell. NCC-melb4 cells provide a model to study the specific stage of differentiation and proliferation of melanocytes. They also express KIT as a melanoblast marker. Using the NCC-melb4 cell line, we investigated the effect of transforming growth factor beta1 on the differentiation and proliferation of immature melanocyte precursors. Immunohistochemically, NCC-melb4 cells showed transforming growth factor beta1 expression. The anti-transforming growth factor beta1 antibody inhibited the cell growth, and downregulated the KIT protein and mRNA expression. To investigate further the activation of autocrine transforming growth factor beta1, NCC-melb4 cells were incubated in nonexogenous transforming growth factor beta1 culture medium. KIT protein decreased with anti-transforming growth factor beta1 antibody concentration in a concentration-dependent manner. We concluded that in NCC-melb4 cells, transforming growth factor beta1 promotes melanocyte precursor proliferation in autocrine and/or paracrine regulation. We further investigated the influence of transforming growth factor beta1 in vitro using a neural crest cell primary culture system from wild-type mice. Anti-transforming growth factor beta1 antibody decreased the number of KIT positive neural crest cell. In addition, the anti-transforming growth factor beta1 antibody supplied within the wild-type neural crest explants abolished the growth of the neural crest cell. These results indicate that transforming growth factor beta1 affect melanocyte precursor proliferation and differentiation in the presence of stem cell factor/KIT in an autocrine/paracrine manner.

Control of KIT signalling in male germ cells: what can we learn from other systems?

“…Treatment with TGFB1 elevates KIT mRNA levels in T-leukaemia cells and in melanoblasts (Tomeczkowski et al 1998, Kawakami et al 2002. In contrast to these two studies that reported a stimulatory impact, the capacity of TGFB1 to reduce KIT levels has been demonstrated in several systems (Heinrich et al 1995, Sansilvestri et al 1995, Hassan & Zander 1996, Bellone et al 1997, Norozian et al 2006).…”

Receptor tyrosine kinases in sinonasal undifferentiated carcinomas—Evaluation for EGFR, c‐KIT, and HER2/neu expression

“…Positive regulators of c-KIT expression, such as bone morphogenic protein-4 (BMP-4) and transforming growth factor-b1 (TGF-b1), have been found in neural crest cells and hematopoietic cells. 42,43 It is possible that increased expression of these proteins may secondarily increase the expression of c-KIT in tumors, although this has not been explored.…”

Expression of the embryonic morphogen Nodal in cutaneous melanocytic lesions

“…It has been hypothesized that the pathogenesis of congenital nevi may be linked to dysregulation of melanocyte migration, proliferation, or differentiation. 18,19 Although other members of the TGF-b family have been shown to influence melanocyte development/differentiation, [20][21][22] a role for Nodal in this process has not been reported. The high expression of Nodal in congenital nevi suggests that Nodal signaling may have as-yet undescribed roles in melanocyte specification, proliferation, migration, and/or differentiation.…”